March 02, 2005

Hypofrontality as early Schizophrenia marker

A new study in the British Journal of Psychiatry has identified hypofrontality (lower metabolic activity in the frontal regions of the brain during an attention task) as a possible early marker of schizophrenia. The authors suggest that identifying hypofrontality with an MRI scan following a first-break episode may be a way to separate people who will likely develop schizophrenia from people who have experienced a psychotic episode for another reason.

The sample size was small (13 subjects) and limited to all males. All subjects were given an MRI scan during an attention task (to activate the frontal brain regions) during hospitalization for a first-episode psychotic break. Subjects were then followed for up to two years, to determine which developed the full diagnostic criteria for schizophrenia. All participants were given the same treatment (haloperidol) to treat their psychosis upon hospital admission; up until that point, no other antipsychotic medications had been taken.

Results after 2 years showed that those men who were eventually given a schizophrenia diagnosis had more marked hypofrontality in the dorsolateral prefrontal cortex. The remainder of the MRI group recieved the diagnosis of acute psychotic episode; they had no recurrance of psychosis during the 2-year follow-up period, and no incidence of negative or disorganized symptoms. MRI scans from the thirteen subjects were also compared to scans from a control group. Both the schizophrenia and the non-schizophrenia groups showed greater hypofrontality than this control group; however, the schizophrenia group had the greatest out of all three groups.

Despite confounding variables (small homogenous sample size), the authors conclude that identifying hypofrontality in the dorsolateral prefrontal cortex after an acute psychotic episode may be an early marker for schizophrenia. However, such hypofrontality may also be a marker of other disorders such as bipolar disorder or psychotic depression.

Study title: "Hypofrontality in Men with First Episode Psychosis" (Brit J Psych)